1. Field of the Invention
This invention relates to an antenna device, more particularly to an antenna device that includes an isolating unit.
2. Description of the Related Art
Wireless technology nowadays requires the existence of multiple antennas that operate in nearly the same frequency. For the purpose of miniaturization, the antennas are kept closely together which make them liable to mutual interferences. Hence, the isolation of the antennas is a problem yet to be solved.
Conventionally, an antenna device is isolated with a slit formed at the electrical ground. The slit generates inductance and capacitance, which generates a bandstop frequency.
The aforementioned conventional antenna device is disadvantageous in that it is not possible to replace the slit with any other LC circuit, which restricts modifications of all circuit elements. Moreover, the inductance generated by the slit is difficult to model. As such, the bandstop frequency generated by the slit will be very difficult to calculate. Further, the foregoing layout restrictions necessary for the conventional way of isolation requires a relatively larger physical area.